The newest generation of reactors features more backup defenses, notes Irwin. Last month, the NRC approved permits for construction of two reactors at Southern Company’s Vogtle, Georgia, nuclear station using the Westinghouse AP1000 design, which has a passive cooling capacity: an elevated reservoir that can be gravity-fed to keep its reactor cool for three days with no electricity. “This 72 hours would have helped greatly [at Fukushima], allowing operators to direct much-needed personnel resources to restoring backup onsite power,” says Blandford.
AP1000’s passive cooling could, of course, fail to operate after a hurricane, tornado, or other calamity greater than the engineers at Westinghouse and the NRC have anticipated. In that event, an AP1000 would have to fall back on conventional power-driven pumps, says Edwin Lyman, a nuclear safety and security expert with the Union of Concerned Scientists. The problem, says Lyman, is that such backup equipment has been winnowed to reduce costs. “If you have a seismic event, for example, that backup may not be available when you need it,” suggests Lyman.
Other experts say the industry’s new voluntary emergency response program will fill such gaps by placing equipment such as portable pumps in regional depots, hopefully beyond the reach of the events that strike a nuclear reactor. “We don’t know what the next rare phenomenon will be, but we’ll be prepared to provide water to the core,” says Andrew Kadak, a professor of nuclear science and engineering at MIT.
But Lyman says NRC audits of voluntary safety upgrades made by the nuclear industry after the September 11 attacks revealed that much of the added equipment was commercial grade, as opposed to higher-grade equipment certified for use in a nuclear plant. “We question whether it would be effective in the heat of an event like Fukushima,” says Lyman. Without greater oversight from the NRC, he says, the industry’s regional depots could similarly fall short of their promise.
In Japan, where nuclear power has, until recently, underpinned the nation’s energy strategy, the inadequate disaster preparation laid bare last year has fueled an antinuclear backlash. If the result is a nuclear phase out, the nuclear industry will have its own propaganda to blame, according to a report on the Fukushima accident’s causes issued last week by an independent commission chaired by Koichi Kitazawa, an expert in materials science and superconductivity and former president of Japan’s Science and Technology Agency.
As the commission’s summary notes, Tepco’s nuclear energy division understood as early as 2006 that some tsunami researchers believed that a tsunami in 869 A.D. would have crested well above Fukushima Daiichi’s seawalls. But the industry judged that raising seawalls and other such high-profile safety upgrades would call its myth of “absolute safety” into question. As the report puts it: “Power companies found themselves caught in their own trap.”